Process of making glue and the like.



' UNITED STATES PATENT oFFIon 1 WILLIAM M. GROSVENOB, OF RIDGEWOOD, NEW JERSEY, ASSIGNOR TO PERKINS GLUE CO., A CORPORATION OF PENNSYLVANIA.

No Drawing.

To all whom it may concern:

Be it known that I, WILLIAM M. GRosvn- NOR, a citizen of the United States, and a resident of Ridgewood, county of Bergen and State of New Jersey, have invented certain new and useful Improvements 1n Processs of Making Glue and the like, of which the following is a specification.

My invention relates more particularly to improvements in processes for making vegetable glue, and especially to improvements over the processes described in United States Letters Patent, No. 1,020,656 and Reissue Letters Patent No. 1336- According to the specific examples described in those patents, a suitable carbohydrate base was first treat- .ed to decrease its water absorptive properties, or so proportion the relative viscosity, cohesiveness and adhesiveness of the resuiting product, when the carbohydrate was dissolved in a small amount of water and alkali, that the resulting product was suitable for gluing up veneers. After th1s prel minary treatment, the carbohydrate was then, according to those processes, dlssolved 1n alkali and water to form glue. Therefore, according to the specific examples set forth in those patents, a certain degeneration of the starch o'r carbohydrate, or a certain proportioning of resulting viscosity, cohesiveness and adhesiveness, was obtained before it was put into solution. Such preliminary treatment consumes much time and labor, and it is the main object of this lnventionto provide a modified process which may be carried out in practically one. stage and in a much shorter time, and with less labor and expense. In meeting this object I have discovered that in colloidal solutions of certain carbohydrates such as starch, a marked change may be produced. in the properties of the solution by prolonged stirring. With certain colloidal solutionsof starch,- caustic soda and water, which when first mixed are very viscous, and even gelatinous, I find that -with prolonged stirring ,the solution may be made quite liquid. In fact, such an adhesive solution which would not have the desired viscosityto be applied by machine I i 3 *tion inthe factory requires it. For instance,

for gluing up veneers may. be made su ciently liquid for this purpose by such pro'+' the afternoon and then allowed to stand over night, after which it maybe stirred for about five hours before using the next day.

molecular structure of the solution whereby it may be given the necessary permanent relative viscoslty, cohesiveness and adhesive- Speeification of Letters Patent. Patented Oct. 10, 1916.v Application filed November 25, 1913. Serial No. 733,317.

ness properly proportioned to form a glue suitable for gluing up wood and capable of being applied by machinery. This. molecular change, I believe, comprises a certain degeneration of the starch, or reduction of its molecular dimensions, in the. solution which consists in decreasing the extension of the side chains on the molecules to form a solution with shorter or fewer molecular side chains, which, I believe, accounts for the increase in fluidity.

As an example of my invention for making glue I take 250 lbs. 'of raw cassava starch or meal of medium quality and suspend thesame in 800 lbs. of water. The mixture is then stirred for one-half hour. With continued stirring I then add 25 lbs. of caustic soda dissolved in 75 lbs. of water. This caustic soda solution is added to the batch gradually but quite rapidly taking, say, only one-half hour for putting in the entire amount of caustic. the caustic causes the starch to pass over into what I believe can be best termed a colloidal solution of starch alkali and water. This solution, however, does not have the desired viscosity, adhesiveness and cohesiveness properly proportioned for a commercial glue. Principally it is too viscous. In order, therefore, to give to the mixture the de- The addition of sired viscosity, coheslveness and adhesiveness, and increase its fluidity, I continue the stirring for five hours or until the batch has acquired the necessary permanent fluid-- ity and spreadability, so that it is applicable I 1 riods, especially-where convenience of opera 1 the batch may be stirred for five hours in In such case, however, only about three parts 7 of water to one part by weight of dry starch should be used.

; The desired endpoint of the alkali treat ment' isconsidered as reached when the viscous, thread-drawing product acquires the I necessary spreadability. The fluidity and spreadability may be tested by inserting a stick in the batch and then withdrawing the same' When the glue will'flow from the stick steadily and evenly without breaking off, the stream becoming thinner and thinner until only avery fine thread remains, and when it can be easily spread on the hand and shows an extremely tenacious adhesive-- ness, then the glue is considered to have the desired properties. If this point of spreadability has not been reached the stirring or standing-for "both, may be continued with,-

out further addition of alkali. until the desired reaction is completed.

- The total amount of water put "into the batch is preferably kept down to about three parts or less by weight to one part by weight of. starch; "If too .much water is used the resulting batch doesn'ot have sufiicient body or adhesiveness to be suitable for a commercial wood glue. However, the amount of water may be varied to some extent but preferably it s hould be lessened if a glue of ex- I-ceptional binding power is desired. Also .ried although; preferably 0 cess should be used over what is necessary. to cause the carbohydrate to pass over into a substantially clear-colloidal solution. The

the amount of caustic soda or other equivalent'solventof the starch mg be widely vay a slight exercentage ofc'austicmay be much decreased 1f theprocess is, carried out with heat, the

amountotalkali required being decreased according: as fthetemperature .used is increased. The addition of the'caustic in the .above example iswmade so qu'ickl. that the starch-is putinto 'solution before 1t has been degeneratedtoward-soluble starch or dex-- 'trin to any mat erial ;extent, butthe. glue is 'ven the desired spreadability particu- 1 lar y im ortant for; machine application-by thesuita ly prolonged action thereof after the starch has gone intosolution.

I Although I .,have described my improvements 'ini great detail with respect to one particularembodiment of the invention, nev- I crtheless', 1' do not desire to be limited to co. improvements,; whatl claim asfnew and desuch'details except as clearly specified in the appended claims, since many changes, modifications and other adaptations. may made without departing from the'ispirit and scopeof' my invention m its broader: aspects.

Having fully, and clearly" described my sire ,tosecure by Letters Patent, is

* 1. The f provedprocess of making glue which consists in suspendingcassava starch in water and then rapid stirring a solution of caustic alkali, the addition being done so quickly that the starch is put into solution before it has been degensume the necessary permanent relative fiuidity, adhesiveness and cohesiveness suitable for gluing up veneers.

3. The improved process for making glue of the starch, and then stirring the batch to reduce its viscosity until the batch has necessary permanent fluidity to be applied by machinery for gluing wood.

4. The improved process of making wood glue which consists in making a solution of starch in alkali and water which has not the necessary permanent fluidity, and then stirring the batch to increase the fluidity thereof until it has the necessary permanent fluidity for wood work.

5. The improved process of making wood glue which consists in making a solution of starch in alkali and water which is too viscons, and then stirring the batch'for about five hours or more. until it becomes sufficiently permanently fluid to be applied by machinery for gluing up veneers.

6. The improved process of making ve-' neer glue, which consists in decreasing the viscosity of a colloidal solution of starch and water, the amount of water present being about three parts or less by weight to one part by weight of starch, by giving the batch '85 which consists in mixing starch, caustic andv about three parts by weight of water to one part by weight of starch to form a solution a prolonged stirring to increase the fluidity thereof and render the fluidity substantially permanent. v 7. The improved process of making glue which consists in suspending starch in water and. then adding alsolution of caustic, the

total amount of waterbeing about threeparts or less by weight to one part of starch and the amount of caustic being sufficient to putthe starch intocolloidal solution, and

thenstirring the batch until its fluidity hasbeen increased to a 'po'intwhere it has the necessary permanent fluidity for wood work. 8. The improved process of making glue which consists insuspending cassava starch.

in water and then adding a solution of caustic, the total-amount of water being about three parts or less by weight to one part of starch and the amount of caustic being suflicient to put the starch into colloidal solution, and then stirring the batch for about five hours or more until its fluidity has been increased to a point where it has the necessary permanent fluidity for gluing wood.

9. The improved process of making glue which consistsin suspending starch in water and then adding alkaliwith agitation, the

of until it has the necessary permanent fluidity for application by machinery for gluing Wood.

11. The improved process of maln'ng glue which consists in suspending a starchy carbohydrate in water and then adding a. solution of caustic, the total amount of water being about three parts or less by weight to one part of carbohydrate and the amount of caustic being sufficient to put the carbohydrate into colloidal solution, and then agitating the batch until its fluidity has been increased to a point where it has the necessary permanent fluidity for application by machinery for gluing wood.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

WILLIAM M. GROSVENOR.

Witnesses GORHAM CROSBY, ADAM SCHMIDT. 

